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John Mcpartland

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So we bought our AR240 last june and it just never seemed run right. I just thought it was me being new to jet boats, I had posts about not being able to surf with 3 adults and 4 kids under 10 in the boat. We couldn't get the boat to plain. Fastforward to today, we had 5 adults ( the largest,me at 208) and 5 kids under 12 and the couldn't get above 16mph at 8k rpm. At the end of last season i filled all the gaps in yje intake and sanded smooth thinking that may be the problem, obviously not. Any ideas? I'm going to take it into the dealer tomorrow?
Thanks
John
 

robert843

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I know stupid question but I gotta ask you are sure the clean out plugs were in and set correctly?
 

Bruce

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Something is wrong with your jet pumps. Being under warranty I would take her to the dealer and not accept her back until she runs 50 with one person and half a tank of fuel.
 

Julian

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So we bought our AR240 last june and it just never seemed run right. I just thought it was me being new to jet boats, I had posts about not being able to surf with 3 adults and 4 kids under 10 in the boat. We couldn't get the boat to plain. Fastforward to today, we had 5 adults ( the largest,me at 208) and 5 kids under 12 and the couldn't get above 16mph at 8k rpm. At the end of last season i filled all the gaps in yje intake and sanded smooth thinking that may be the problem, obviously not. Any ideas? I'm going to take it into the dealer tomorrow?
Thanks
John
Yeah....sounds like your clean out plugs were not in, or not in fully. Pretty simple fix....no dealer required.

To surf you need ballast....lots of it.
 

Beachbummer

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Gates fully clearing the pump exit when all the way forward? Any obstructions in the pump?? What's max RPM? Somethings not right...
 

John Mcpartland

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Yeah....sounds like your clean out plugs were not in, or not in fully. Pretty simple fix....no dealer required.

To surf you need ballast....lots of it.
I have ballast but couldn't even try since i couldn't get about 15mph without any ballast filled. I just finished installing my ballast last week and haven't been able to even test it yet.
 

John Mcpartland

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Gates fully clearing the pump exit when all the way forward? Any obstructions in the pump?? What's max RPM? Somethings not right...
Something is wrong with your jet pumps. Being under warranty I would take her to the dealer and not accept her back until she runs 50 with one person and half a tank of fuel.
My thoughts exactly
 

John Mcpartland

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Another thing i noticed that doesn't seem right, is when in reverse at full throttle the boat doesn't really go in reverse. Maybe at about 2mph
 

Bruce

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Another thing i noticed that doesn't seem right, is when in reverse at full throttle the boat doesn't really go in reverse. Maybe at about 2mph
Reverse at full throttle is just cavitation. Jets do not allow for high speed reverse.
 

DBamaC

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Another thing i noticed that doesn't seem right, is when in reverse at full throttle the boat doesn't really go in reverse. Maybe at about 2mph
Maybe an issue with your bucket adjustment?
 

Bruce

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Can you post pictures of your impellers reaching your phone up through the intake grate and from behind with the throttle lever forward?
 

Julian

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Yes. I actually made a gasket to put in the plug to trouble shoot
Does it sound like it is cavitating? Clearly something wrong with the pumps if the engines are running fine and no thrust is produced.
  1. Plugs are allowing air by them
  2. Wear rings are out of spec....worn by sand/gravel ingestion?
  3. Intermediate bearings damaged allowing air by
  4. impellers are damaged
Could be just on one engine too. If you've tried much of the above, I agree with Bruce....take it to a dealer for their diagnosis.
 

Julian

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With everybody off the boat and just myself i could get to 38-42. But it took awhile. 45-60 seconds
That is interesting.....absolutely a cavitation issue then in my opinion. Did you modify the plugs somehow with this "gasket" you reference?
 

swatski

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Please do not take offense with what I'm going to ask. I have done it a couple of times now, so I know it can happen, especially with a bunch of kids on board when I'm losing my mind.
So, here it goes. Are you positive both engines were running? What you are describing could be just running with one engine on.
(please don't shoot; I have done that myself and that's why I'm asking)

--
 

Betik

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Being there done that LOL
Thanks god it was on the no wake area
 

John Mcpartland

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That is interesting.....absolutely a cavitation issue then in my opinion. Did you modify the plugs somehow with this "gasket" you reference?
Yes. Before i always jad rhe clean out tubes full of water. After no water at all
 

John Mcpartland

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Please do not take offense with what I'm going to ask. I have done it a couple of times now, so I know it can happen, especially with a bunch of kids on board when I'm losing my mind.
So, here it goes. Are you positive both engines were running? What you are describing could be just running with one engine on.
(please don't shoot; I have done that myself and that's why I'm asking)

--
Yep. Both engines on. I also tried using my ridesteady to gradually increase speed to try to get up to speed or even plain
 

John Mcpartland

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Can you post pictures of your impellers reaching your phone up through the intake grate and from behind with the throttle lever forward?
Can you post pictures of your impellers reaching your phone up through the intake grate and from behind with the throttle lever forward?
20180617_203240.jpg 20180617_203220.jpg 20180617_202217.jpg 20180617_202210.jpg
 
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